Telephone trunking system.



B. C. GROH.

TELEPHONE TRUNKING SYSTEM.

APPLICATION FILED MAR. a. 1915. RENEWED JULY 19. 1918.

1 29 415 Patented Feb. 4, 1919.

NT @FFTGE.

BERNARD C. GROH, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC ELECTRIC coiur OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TELEPHONE TRUNKING- SYSTEM.

aaeaaia.

hpeoification of Letters Patent.

Patented Feb. 4:, rate.

Application filed March e, 191%, serial No. 12,704. Renewed July 19, rate. Serial No. 2%,772.

To all whom it may concern:

Be it known that I, BERNARD C. GRoH, a citizen of the United States of America, and a resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Telephone Trunking Systems, of which the following is a specification.

My invention relates in general to telephone trunking systems and more partlcularly to methods of trunking or, through switching, as it is usually termed, between long distance lines terminating at an intermediate or switching station. The switching of toll lines for the establishment of through connections has .been done manually in the past, throu h the medium of operators at the switching station, and the principal object of my invention is the production of an automatic toll switching system whereby through connections may be established by automatic switches under control of an operator at a distant toll board and without the assistance of operators at the switching station.

Further objects of the invention relate to circuit improvements whereby well known types of automatic switches are used in conjunction with well known manual equipment to form a complete and efiicient automatic toll switching system.

The invention relates also to the provision of means for setting up an automatic connection between the calling and-called! lines after the called line has been signaled and for disconnecting the called line from its normal connection to the operators board and for retaining supervision over the automatically with B she together two lines.

Fig. 3 shows the switching station equipment of two toll lines.

Referring to Fig. 1, A and B represent outlying towns which are connected with the c1ty C by means of toll lines t. It will be seen that these toll lines t loop throu h the switching station S before entering t e toll board T in the city C. Heretofore, the method of operation has been as follows: Suppos ng that the operator at A desires connection with B, the operator atAb ringing on her toll line causes a signal to e displayed at the toll board T in the city C. The operator at T goes in on the line and upon findm that a connection is desired epresses an order wire key leadlng to an operator at the switching station S and orders toll line A switched through to toll line placed in the outskirts pomt where the 0 en wire toll lines are connected to the un erground cable system, it will be seen that this through switching eliminates several miles of cable circuit with the toll board equipment of B. As the switching station iswhen a through connection is (put up. It is the object of this invention to lsclose means by wh1ch the operations at the switching station S may be controlled wholly by the operators at the toll board T, thus eliminatlng the operators at the switching station.

The cord circuit T (Fig. 1) is a well known type of cord circuit comprising the usual answering and calling plugs P and P, respectively, inductively connected through the medium of the condensers 2 and 3. The lamps 4 and 5 are the usual supervisory lamps and are controlled by the supervisory relays 6 and 7, respectively. The keys K and K are the usual ringing keys, keys K, K and K are the usual listening keys, the key K when operated, disconnects the answering and callin ends of the cord circuit. The key K 1s a calling device key, the purpose of which is to connect a calling device with the cord circuit, through the medium of which the operator may con-' trol the automatic switches to set up the proper connection. This calling device may that shown in British Patent to S. G. S. Dicker No. 29,654 of 1910, through the medium of which calling device the operator may interrupt the simplex circuit a de- "sired number of times for each of the digits March 13, 1906, to Keith, Erickson and Erickson, the circuits, however, being notified to adapt the switch to operate 1n a system embodying the principles of my invention. Among other details, the connector H comprises a bank of contacts arranged in horizontal rows or levels, which contacts are adapted to be engaged by a set of wlpers, 10, 11 and 12 carried upon a shaft (not shown) which has a vertical movement controlled by the vertical magnet 13 and a rotary movement controlled by the rotary magnet 14. The usual side switch comprising the Wiper 15 is controlled by the private magnet 16 in the usual and well-known manner. The operations of various parts of the switch are controlled through the medium of the line relay 17. Means for permitting the switch to be restored to normal position, are provided in the release magnet 18, which, upon energizing, withdraws the retaining double-dog from the shaft, thereby causin the shaft and wipers to be returned to t eir normal position. The springs 19 close only when the switch shaft has been raised one or more steps from its lowest position. The relays 20 and 21 are slow acting, that is, slow to release their armatures upon denergizing. The connector switch H associated with the toll line B is similar to ,the connector switch H.

For the purpose of supplying battery current for operating the apparatus there is shown the battery B having-one terminal grounded at G. Although there is shown only one battery in the drawings, a plurality of batteries may be provided, that is, a battery at the switching station S and one at the toll board T. For the purpose of supplying ringing current there is shown the ringing current generators R and R.

A general description of the apparatus having been given it will now be explained how a connection may be completed from toll line A to toll line B. It will be asipmed that, the circuit number of toll line When an operator upon the toll line Y desires connection with the toll line B, she impresses ringing current upon the toll line A which induces an alternating current in the following circuit, from point 22 through wlndmg 23 of repeating 0011 C, springs 24, springs 25, springs 26, right hand winding of relay 8, springs 27, springs 28, springs 29, and thewinding 30 of repeating coil C to polnt 22. This alternating current energizes relay 8, which, upon energizing, forms a locking circuit for itself from ground Gr through s rings 31 and 32, springs 33 and 34, and t e left hand winding of relay 8 to battery B. In addition the relay 8, upon energizing, closes a circuit from ground G through springs 31 and 32, springs 33, 34 and 35, and lamp 36 to battery B. The operator at T upon seeilig the lamp 36 glowmg, mserts the plug into the jack J, whereupon a circuit is formed from ground G through springs 37, springs 38 and 39, sleeve of plug P and sleeve of jack J, relay 9 to battery B. The relay 9, upon' energizing, removes the winding of relay 8 from across the line, extinguishes the lamp 36, and closes a circuit from ground G through all the visual busy rela s, associated with that line to battery B. The energization of the visual busy re ays informs the operators at the multiple positions that the toll line A is busy. The operator at T then operates the-key K, to connect her talking set (not shown) across the calling line and converses wlth the operator at A. Upon learning thata connection is desired with toll line B, she inserts the plug P into a multiple jack M of the toll line B. The insertion of the plug P causes the line relay to be removed from the toll line Band the visual busy relays to be operated in a manner similar to that described in connection with the plug P. The operator at T then depresses the key K to impress ringing current on the toll line B, and upon the res onse of the operator at B, the operator at presses the key K to the left and operates the calling device 40 for the digits of the circuit number of the toll line B.

When the key K is pressed to the left, a circuit may be traced from ground (Sr through 'line relay 17 to point 22, through the wlndings 23 and 30 in parallel, the two sides of the line and of the cord circuit in parallel, the two windings of relay 6 in parallel, key K and the calling device 40 to battery B. The relay 6 is differentially wound and will not 0 erativel'y energize at this time, the relay 1 however will energize and close a circuit throng relay 20. This circuit extends from ground G through contacts of springs 41 and 41 and relay 20 to battery B. The operator at T now operates the calling device 40 for the first d1g1t two of the number of toll line aacaeas device pulse springs are se arated twice ;momentari ly,- each time brea 'ng the circuit of the line relay 17 of the connector H;

The'relay 20 of the connector being slow acting does not deenergize during the momenta interruptions of its circult by 'the relay 1 and consequently each time the latter relay denergizes an impulse is transmitted overthe circuit extending from ground G through springs 41 and 42, springs 43 and 44, relay 21, vertical magnet 13, side switch wiper 15 (in first positlon) to battery B. The vertical magnet receives two impulses over this circuit and operates to raise the switch shaft and wipers two steps, to a osition opposite the second row orlevel of ank'contacts, and, at the same time the shaft controlled springs 19 are closed. The slow acting relay 21 is maintained in its energized position continuously while impulses are being transmitted to the vertical magnet through it, and in its ener 'zed position closes a circuit from ground 5 through springs 45, private magnet 16 to battery B. This circuit is broken when the relay 21 denergizes after the last impulse has been delivered to the vertical magnet, and the breaking of said circuit causes the private magnet 16 to deenergize, thus permitting the sideswitoh to ass to second position. In passing from rst to second position the side switch wiper 15 transfers the battery connection from the vertical magnet 13 to the rotary magnet 14.

The operator at T now operates the calling device 40 for the second digit, two, of the number of toll line B, in response to which the connector line relay operates to transmit two impulses through the rotary magnet 14 whereby the shaft wipers are rotated onto the bank contacts associated with the toll line B. The circuit of the rotary magnet extends from ground G through springs 41 B, whereby the cdll lr and 42, springs 43 and 44, relay 21, rotary ma net 14, side switch wiper 15 (in second posltion) to battery B. The relay 21- operates in response to this digit, in the same manner as for the previous digit, to cause the private magnet 16 to advance the side switch to third position. By the engagement. of the side switch wiper 15 with 1ts third position contact point circuits are formed as follows: from ground G through relay 46, private wiper 11, side switch wiper 15 (in third position) to battery B. The re lay 46, upon energizing, disconnects that part of toll line B which extend from the switching station to the toll board. A second circuit is formed from G" through the relay 47, side switch wiper 15 (in third position) to battery B, and the relay 47, upon energizin removes the shunts from around the imp ance coils 48 and 49.

It will be seen that the toll lines A and B are now directly connected at the switching station and that the relay 6 at the cord circuit T is bridged acrom the toll line A, but

a in series with the impedance coils 48 and 49.

These coils are of so hi h an impedanw that the relay 6 W111 not e ect the transmission,

but after the conversation is completed and either of the operators ring 0d, the relay 6 W111 receive enough current tobe operated. The relay 6, upon operating, removes the immediately energizes and locksup through the cut-ofi' relay 9 and closes a circuit through the lamp 4, this causes the said lamp to glow. The operator at T, upon seeing the lamp 4 glowing, operates the key K and inqulres if the connection has been termmated, and, if it has, she thereupon removes the plugs P and P from their respectlve Jacks at the same time restoring the key K to normal. The removal of the plug P opens the circuit of the relay 17, which relay, upon deenergizing, opens the circuit of relay 20. The relay 20, upon denergi'zing, closes a c1rcu1t from ground G; through shunt from around the relay 50, ,which relay springs 41 and 42, SPI'IIIgS-43 and 51, re-

may be interconnected automatically at the latter point under the control of an operator at the toll board, and entirely independent of manual assistance at the switching station.

While I have found it convenient in ex-' plaining my invention to show a certain specific embodiment thereof, I am aware that changes may be made to adapt the invention to various operating methods and systems, and I do not, therefore, wish to limit myself to the exact embodiment shown and described, but desire rather to include and have protected by Letters Patent all forms and modifications of my invention which may hereafter be devised, limited only by the scope of theappended claims.

What I claim as my invention is:

1. In a telephone system, a line, an automatic switch associated with said line, a' second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, an auxiliary circuit associated with the branch circuit of the first line, means for connecting the auxiliary circuit and said. last mentioned branch circuit, means individual to said auxiliary circuit for operating said switch over said last mentioned branch circult to extend a connection from the first to the second line, and means controlled by said switch for disconnecting the second line from its branch circuit.

2. In a telephone system, a line, an automatic switch associated with said line a second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, a si a1 individual to the branch circuit of sa1d first line, an auxiliary circuit associated with the branch circuit of the first line, means for operating said signal over circuits including the first line, means for connecting the auxiliary circuit and said last branch circuit in response to the operation of said signal, means associated with said branch circuit for operating said switch to extend a connection from the first to the second line, and means controlled by said switch for disconnecting the branch circuit of the second line from the second line.

3. In a telephone system, a line, 'an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, an auxiliary circuit associated with said branch circuits, means for connecting said auxiliary circuit with said second line, a

signal on said second line, a source of signaling current, and means individual to said auxiliary circuit for applying said signaling current to the second line for operating said signal, means for connecting said auxiliary circuit with the branch circuit of the first line, means associated with said auxiliary circuit for operating said automatic switch to establish a connection between the first and the second lines.

4. In a telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said'switch, a branch circuit for said second line, a branch circuit for said first line, an auxiliary circuit associated with said branch circuits, means for connecting said auxiliary circuit with said second line, a signal on said second line, a source of signaling current, means individual to said auxiliary circuit for applyin said signaling current to the second line or operating sa1d signal, means for connecting said auxiliary circuit with the branch circuit of the first line, means associated with said auxiliary circuit for operating said automatic switch to establish a connection between the first and the second lines, and means controlled by said automatic switch for disconnecting the second line from its branch circuit.

5. In a telephone system, a line, an automatic switch associated with said'line, a second line. a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, a si al associated with the branch circuit of sa1d first line, an auxiliarycircuit associated with said branch circuits, means for connecting said auxiliary circuit with said second line, a signal on said second line, a source of signaling current, means individual to said auxiliary circuit for applying said signaling current to the second l1ne for operating sa1d signal, means for o crating said first signal over circuits inclu in the first line, means for connecting said aux1 iary circuit with the branch circuit of the first line in response to the operation of said first signal, and means associated with said auxiliary circuit for operating said automatic switch to establish a connection between the first and the second lines. 6. In a telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, a si al associated with the branch circuit of sa1d first line, an auxiliary circuit associated with said branch circuits, means for connecting said auxiliary circuit with said second line, a signal on said second line, a source of signaling current, means individual to said auxiliary circuit for applying said signaling current to the second line for operating said signal, means for operating said first signal over circuits includin the first line, means for connecting said aux iary circuit with the branch circuit of the first line in response to the operation of said first signal, means associated with said auxilia circuit for operating said automatic swit h to establish a connection between the first and the second lines, and means controlled by said automatic switch for disconnecting the second line from its branch circuit. 7. In a telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a branch circuit for said second line a branch circuit for said first line, an auxiliary circuit associated with the branch circuit of the first line, means for connectin the auxiliary circuit and said last branc circuit, means associated with said branch circuit for operating said switch to extend a connection from the first to the second line, means controlled by said switch for disconnecting the branch circuit of the second line from its branch circuit, supervisory equipment associated with said auxiliary circuit, and means for operating said supervisory equipment over the circuit connecting the two lines from either line.

8. In a telephone system, a line, an autoline, a branch circuit for said first line, a signal associated with the branch circuit of said first line, an auxiliary circuit associated with the branch circuit or the first line, means for operating said signal over circuits including the first line, means for connecting the auxiliary circuit and said last branch circuit in response to the operation of said signal, means associated with said branch circuit for operating said switch to extend a connection from the first to the second line, means controlled by said switch for disconnecting the branch circuit of the second line from the second line, supervisory equipment associated with said auxiliary circuit, and means tor-operating said supervisory equipment over the circuit connecting the two lines from either line.

9. in a telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, an auxiliary circuit associated with the branch circuits, means for connecting said auxiliary circuit with said second line, a signal on said second line, a source of signaling current, means associated with said auxiliary circuit for applying said signaling current to the second line for operating said signal, means for connecting said auxiliary circuit with the branch circuit of the first line, means associated with said auxiliary circuit for operating said automatic switch to establish a connection between the first and the second lines, supervisory equipment associated with said auxiliary circuit, and means for operat-' ing said supervisory equipment over the circult connecting the two lines from either line.

10. In a telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, an auxiliary circuit associated with said branch circuits, means for connecting said auxiliary circuit with said second line, a si nal on said second line, a source of signa ing current, means associated with said auxiliary circuit for applying said signaling current to the second line for operating said signal, means for connecting said auxiliarycircuit with the branch circuit of the first line, means associated with said auxiliary circuit for operating said automatic switch to establish a connection between the first and the second lines, means controlled by said automatic switch for disconnecting the second line from its branch circuit, supervisory equipment associated with said auxiliary circuit, and means for operating said supervisory equipment over the circuit connectmg the two lines from either line.

11. In a telephone system, a line, an autoassociated with said branch circuits, means for connecting said auxiliary circuit with said second line, a slgnal on said second line,

a source of signaling current, means associated with said auxiliary circuit for applymg said signaling current to the second line for operating said signal, means for operat- I ing said first signal over circuits including the first line, means for connecting said auxiliary circuit with the branch circuit of the first line in response to the operation of said first signal, means associated with said auxiliary circuit for operating said automatic switch to establish a connection .between the first and the second lines, supervisory equipment'associated with said auxiliary circuit, and means for operating said supervisory equipment over the circuit connecting the two lines -from either line.

12. In a telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit forsaid first line, a signal associated with the branch circuit. of said first line, an auxiliary circuit associated with said branch circuits, means for connecting said auxiliary circuit with said second line, a signal on said second line, a source of signaling current, means associated with said auxiliary circuit for applying said signaling current to the second line for operating said signal, meansv for operating said first signal over circuits including the first line, means for connecting said auxiliary circuit with the branch circuit of the first line in response to the operation of said first signal, means associated with said auxiliary circuit for operating said automatic switch to establish a connection between the first and the second lines, means controlled by said automatic switch for disconnecting the second line from its branch circuit, supervisory equipment associated with said auxiliary circuit, and means for operating said super visory equipment over the circuit connecting the two lines from either line.

13. In a telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, an. auxiliary circuit associated with the branch circuit of the first line, means for connecting the auxiliary circuit and said last branch circuit, means individual to said auxiliary circuit for operating said switch over said last branch circuit to extend a connectill llti

with the branch circuit of the first line} means for operatixg said signal over circuits including the rst line, means for connecting the auxiliary circult and said last branch circuit in response to the operation of said signal, means associated with said. branch circuit for operating said switch to extend a connection from the first tothe' second line, means controlled by said switch for disconnecting the branch circuit of the second line from the second line, and means for automatically releasing the connection between the two lines.

15. In a telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, an auxiliary circuit associated with said branch circuits, means for connecting said auxiliary circuit with said second line, a signal on said second line, a source of signaling cur rent, means individual to said auxiliary circuit for applying said signaling current to the second line for operating said signal,- means for connecting said auxiliary circuit with the branch circuit of the first line, means associated with said auxiliary circuit for operating said automatic switch to establish a connection between the first and the second lines, and means for automati-' cally releasing the connection between the two lines. v

16. In a telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, an auxiliary circuit associated with said branch circuits, means" for connectin said auxiliary circuit with said second line, a signal on said second line, a source of signaling current, means individual to said auxiliary circuit for applying said signaling current to the second line for operating said signal, means for connecting said auxiliary circuit with the branch circuit of the first line, means associated with said auxiliary circuitfor operating said automatic switch to establish a connection between the first and the second lines, means controlled by said automatic switch for disconnecting the mosaic second line from its branch circuit, and

means for automatically releasing the connection between the two lines.

17. In a telephonesystem, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, a signal associated with the branch circuit of said first line, an auxiliary circuit associated with said branch circuits, means for connecting said'auxiliary circuit with said second line, a signal on said second line, a

first and the second lines, and means for automatically releasing the connection between the two lines. 4

18. In atelephone system, a line, an auto- ,matic switch associated with said line, a

second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, a signal individual to the branch circuit of said first line, an auxiliary circuit associated with said branch circuits, means for connecting said auxiliary circuit with said second line, a signal on said second line, a source of signaling current, means associated with said auxiliary circuit for applying said signaling current to the second line for operating said signal, means for operating said first signal over circuits including. the first line, means for connectin said auxiliary circuit with the branch circuit of the first line in response to the operation of said first signal,- means associated with said auxiliary circuit for operating said automatic switch to establish a connection between the first and the second lines, means controlled by said automatic switch for disconnecting the 'second line from its branch circuit, and means for automatically releasing the connection between the two lines.

19. In a telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch,a branch circuit for said second line, a branch circuit for said first line, an auxiliary circuit associated with the branch circuit of the first line, means for connecting the auxiliary circuit and said last branch circuit, means associated with said branch circuit for operating said switch to extend a connection from the first to the second line, means controlled by said switch i for disconnecting the branch circuit of the second line from its branch circuit, supervisory equipment associated with said auxiliary circuit, means for operating said supervisory equiplnent over the circuit connecting the two lines, and means for automatically releasing the connection between the two lines.

20. In a telephone system, a line, an automatic switch associated with said line, second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, a signal associated with the branch circuit of said first line, an auxiliary circuit associated with the branch circuit of the first line, 'means for operating said signal over circuits including the first line, means for connecting the auxiliary circuit and said last branch circuit in response to the operation of said signal, means associated with said branch circuit for operating said switch to extend a connection from the first to the second line, means controlled by said switch for disconnecting the branch circuit of the second line from the second line, supervisory equipment associated with said auxiliary circuit, and means for operating said super- 7 visory equipment over the circuit connecting Oil the two lines, and means for automatically releasing the connection between the two lines.

21. In a telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, an auxiliary circuit associated with said branch circuits, means for connecting said auxiliary circuit with said second line, a signal on said second line, a source of signaling current, means associated with said auxiliary circuit for applying said signaling current to the second line for operating said signal, means for connecting said auxiliary circuit with the branch circuit of the first line, means associated with said auxiliary circuit for operating said automatic switch to establish a connection between the first and the second lines, supervisory equipment associated with said auxiliary circuit, means for operating said supervisory equipment over the circuit connecting the two lines, and means for automatically releasing the connection between the two lines.

22. In a. telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a branch circuit for. said second line, a branch circuit for said first line, an auxiliary circuit associated with said branch circuits, means for connecting said auxiliary circuit with said second line, a signal on said second line, a source of signaling current, means associated with circuit, supervisory equipment associated,

with said auxiliary circuit, means for operating saidsupervisory equipment over the circuit connecting for automatically releasing the connection between the two lines.

2? In a telephone system, a line, an automatic switch associated with'said line, a second line, a terminal for said second line in said switch, a branch circuit for said second line, a branch circuit for said first line, a signal associated with the branch circuit of said first line, an auxiliary circuit associated with said branch circuits, means for connecting said auxiliary circuit with said second line, a signal :on said second line, a source of signaling current, means associated with said auxiliary circuit for applying said signaling current to the second line for operating said signal, means for operating said first signal over circuits including the first line, means for connecting said auxiliary circuit with the branch circuit of the first line in response to the operation of said first signal, means associated with said auxiliary circuit for operating said automatic switch to establish a connection between the first and the second lines, supervisory equipment associated withv said auxiliary circuit, means for operating said supervisory equipment over the circuit connecting the two lines, and means for automatically releasing the connection between the two lines.

24:. In a telephone system, a line, an automatic switch associated with said line, a second line, a terminal for said second line in said switch, a'branch circuit for said second line, a branch circuit for said first line, a signal associated with the branch circuit of said first line, an auxiliary circuit associated with said branch circuits, means for connecting said auxiliary circuit with said second line, a signal on said second line, a source of signaling current. means associated with said auxiliary circuit for applying said signaling current to the second line for operating said signal, means for operating said first signal over circuits including the first line, means for connecting said auxiliary circuit with the branch circuit of the first line in response to the operation of said first signal, means associated with said auxiliary circuit for operating said automatic switchto establish a connection the two-lines, and means between the first and the second lines, means controlled b said automatic switch for disconnecting t e second line from its branch circuit, supervisory equipment associated with said auxiliary circuit, means for operating said supervisory equipment over the circuit connecting the two lines, and means for automatlcally releasing the connection between the two lines.

25. In a toll switching system, a plurality of toll lines extending through a switching station and then termlnating in manual connective terminals at a toll board, operators equipment for interconnecting sa1d toll lines manually by way of said terminals, automatic switches at the switching station containing multiple fixed terminals of said lines, and means for operating said switches to interconnect said lines automatically.

26., In a toll switching system, a plurality of toll lines extending through a switching station and then termlnating in manual connective terminals at a toll board, operators equipment for interconnecting said toll lines manually by way of said terminals, automatic switches at the switching station containing multiple fixed terminals of said lines, and controlling circuits for said switches accessible to toll operators whereb said lines may be interconnected automatically.

27. In a toll switching system, a plurality of toll lines extendin through a switching station and then terminating in manual connective terminals at a toll board, operators equipment for interconnecting said toll lines manually by way of said terminals, a branch of each toll line terminatin in an automatic switch at the switching station, multiple fixed terminals of said lines in said switches, and means for operating said switches to interconnect said lines automatically.

'28. In a toll switching system, a plurality of toll lines extending through a switching station and then termmating in manual connective terminals at a toll board, operators equipment for interconnecting said toll lines manually by way of said terminals, a branch of each toll line terminating in an automatic switch at the switching station, multiple fixed terminals of said lines in said switches, and controlling circuits for said switches accessible to toll operators whereby said .lines may be interconnected automatically.

29. In a toll switching system, a plurality of toll lines extending through a switching station and then termlnating in manual connective terminals at a toll board operators equipment for interconnecting sa1d toll lines manually by way of said terminals, a branch of each toll line terminating in an automatic switch at the switching station, multiple fixed. terminals of said lines in said switches,-

macaw a controlling circuit for each switch including that portion of the associated toll line extending between the switchingstation and thetoll board, and operator controlled means for actuatin said switches over their respective control lng circuits to interconnect said hues automaticall 30. In a toll swltching system, a plurality of toll lines extending through a switching station and then termlnating in manual connectlve terminals at a toll board, operators equlpment for interconnecting said toll lines manually b way of said terminals, automatic switc es at the switching station each comprising a movable terminal individual to a particular toll line and multiple fixed terminals of all the toll lines, and means for operating said switches to interconnect sa1d lines automatically.

31. In a toll switching system, a plurality of toll lines extendin through a switching station and then terminating in manual connective terminals at a toll board, operators equipment for interconnecting said toll lines manually by way.of said terminals, automatic switches at the switching station each comprising a movable terminal individual to a particular toll line and multiple fixed terminals of all the toll lines, and controlling circuits for said switches accessible to toll operators whereby said lines may be interconnected automatically.

32. In a toll switching system, a plurality of toll lines extending through a switching station and then terminating in manual connective terminals at a toll board, operators equipment for interconnecting said toll lines manually by way of said terminals,.automatic switches at theswitching station each comprising a movable terminal individual to a particular toll line and multiple fixed terminals of all the toll lines, a controlling circuit for each switch including that portion of the associated toll line extending between the switching station -and the toll board, and operator controlled means for actuating said switches over their respective controlling circuits to interconnect said lines automatically.

33. In a toll switching system, a plurality of toll lines extending through a switching station and then terminating at a toll operators position, manual equipment for answering calls received over said lines, automatic switches at the switching station each comprising a movable terminal individual to a particular toll line and multiple fixed terminals of all the toll lines, and means for operating said switches to interconnect said lines automatically.

34. In a toll switching system, a plurality of toll lines eXtendin through a switching ators position, manual equipment for aaeaaie answering calls received over said lines, au-

tomatic switches at the switching station containing multiple fixed terminals of said lines, and controlling circuits for said switches accessible to toll operators whereby said lines may be interconnected automatically.

35. In a toll switching system, a plurality of toll lines extending through a switching station and then terminating at a toll operators position manual equipment for answerin calls received over said lines, a branch oi each 'toll line terminating in an automatic switch at the switching station, multiple fixed terminals of said lines insaid switches, and means for operating said switches to interconnect said lilies automatically. v a I 36. In a toll switching systemya' plurality of 'toll lines extending througha' switching station and then terminating at a toll operators position, manual equipment for answering calls received over said lines, a branchof each toll line terminating in an automatic switch at the switching station, multiple fixed terminals of said lines in said switches, and controlling circuits for said switches accessible to toll operators.

whereby said lines may be interconnected automatically.

37 In a toll switching system, a plurality of toll lines extending through a switching station and thenterminating at a toll operators position, manual ;equipment 'for answering calls received over said lines, a branch of each toll line terminating in an automatic switch at the switching station, multiple fixed terminals of said lines in said switches, a. controlling circuit for each switch including that portion of the associated toll line extending between the switching station and the toll board, and operator controlled means for actuating said switches over their respectivecontrolling circuits to interconnect said lines automatically.

38. In a toll switching system, a plurality oftoll lines extending through a switching station and then terminating at atoll operators position, manual equipment for answering calls receivedover said lines, an tomatic switches at the switching station each comprising a movable terminal individual to a particular toll line and multiple fixed terminals of all the toll lines, and means for operating said switches to interconnect said lines automatically.

39. In a toll switching system, a plurality of toll lines extending through a switching station and then terminating at a toll operators position, manual equipment for answering calls received over said lines, automatic switches at the switching station each comprising a movable terminal individual to a particular toll line and multiple fixediterminals of all the toll lines, and controlling circuits for said switches accessible to toll operators whereby said lines may be interconnected automatically.

(iii

40. In a toll switching system, a plurality trolling circuit for each switch including that portion of the associated toll line extending between the switching station and the toll board, and operator controlled means for actuating said switches over their respective controlling circuits to interconnect said lines automatically.

41. In a telephone system, a plurality of lines each 7 having three branches, the branches of each line extending, respectively, to an operators position, a movableterminal of an automatic switch, and a multiple fixed terminal in each of said switches, and

an operators controlling circuit for each switch including the associated first branch whereby any switch may be operated 'to connect its associated line with any one of the other lines. I

42. In a telephone system, a plurality of lines each having three branches, the branches of each line extending, respectively,

-to an operators position, a movable terminal of an automatic switch, and a multiple fixed terminal in each of said switches, an operators controlling circuit for each switch including theassociated first branch whereby any switch may be operated to connect its associated line with any one of the other lines, and operators equipment for interconnecting any two of said lines manually independent of the associated switches.

43. In a telephone system, a plurality of lines each having three branches, the branches of each line extending, respectively, to an operators position, a movable terminal of an automatic switch, and a multiple fixed terminal in each of said switches, an operators controlling circuit for each switch including the associated first branch whereby any switch may be operated to connect its associated line with any one of the other lines, and means for disconnecting the branch of any line Which extends to the operators position when such line is seized by one of said switches.

44. In a telephone system, a line provided at one end .with first and second branches terminating, respectively, in an automatic switch and in an operators position, other lines accessible to said switch, a controlling circuit for said switch including the conduc-= are tors of said second branch in parallel, and means controlled by an operator for transmitting current impulses over said circuit to operate said switch to connect said first line with one of said other lines.

45. In a telephone system, a plurality of lines each terminating in an automatic switch, a multiple fixed terminal of each line in each switch, a branch of each line extending to an operators p0sition,'means at the operators position for answering calls received over said lines by way of said branches, and operator controlled means for operating any switch to extend its associated line into connection with any one of the other lines. Y

46. In a toll switching system, a plurality of toll lines each terminating in an aut0- matic switch, multiple fixed terminals of said lines in said switches, a branch of each line extending to anoperators position, and a controlling circuit for each switch including a conductor of the associated branch.

47. In a toll switching system, a plurality of toll lines each terminating in an 'automatic switch, multiple fixed terminals of said lines in said switches, a branch of each line extending to an operators position, means at the operators position for answering calls, and an operators controlling circuit for each switch whereby any switch may be operated to connect its associatedline with any one of the other lines.

48. In a toll switching-system, a plurality of toll lines each terminating at a switching station in an automatic switch, multiple fixed terminalsof said lines in said switches, a branch of each line extending to a toll board, and a controlling circuit for each switch including the conductors of the associated branch in parallel.

49. In a toll switching system, a plurality of toll lines extending via a switching station to a toll board, operators equipment including cord circuits at the toll board, automatic switches at the switching station controllable from the toll board, and means whereb operators may at their option connect said toll lines manually by Way of said cord circuits or automatically by way of said switches.

Signed by me at Chicago, Cook county, Illinois, this th day of February, 191-5.

BERNARD G. GROII.

Witnesses:

ALBERT ANDERSEN, CHAS. M. CANDY. 

